Neuroimaging Use Soars in the ED

Nancy A. Melville

August 11, 2021

The use of neuroimaging in emergency departments increased by more than 70% between 2007 and 2017, with head and neck computed tomography angiography (CTA) in older patients leading the way. Experts say the increases are consistent with increasing access to the technology and stepped-up efforts to use those tools whenever possible to save lives.

"The growth observed in head and neck CTA was substantial over the study period in the commercially insured and Medicare Advantage populations, outpacing that of other neuroimaging modalities," the authors report.

"The necessity of the rapidly growing utilization of CTA should be monitored as the indications for CTA expand," co-author Selin Merdan, PhD, of the Georgia Institute of Technology in Atlanta, told Medscape Medical News in an interview.

Andrew ElHabr

For the study, published this month in the American Journal of Roentgenology, first author Andrew ElHabr, also of Georgia Institute of Technology, and colleagues evaluated data on the use of neuroimaging in EDs over a decade. They used information from a large database of patients with private health insurance as well as Medicare Advantage, in Optum's De-identified Clinformatics Data Mart database.

The sample started with 202,797 individuals in 2007 and increased to 797,825 by 2017. Of note, the proportion of individuals over age 65 increased substantially — from 42% in 2007 to 83% in 2017 — as more were enrolled in Medicare Advantage.

After adjusting for age, the increase in the use of ED neuroimaging per 1,000 visits over the study period was 72%, representing a compounded annual growth rate (CAGR) of 5%.

The increases for head CT and head MRI in the ED were 69% and 67%, respectively (both also a CAGR of 5%).

The age-adjusted increase for head CTA per 1000 ED visits was much higher: 1100%, for a CAGR of 25%, and the increase in usage of neck CTA was even higher: 1300% (CAGR 27%).

Non-CT imaging increases were not as substantial, with head MR angiography (MRA) increasing by 36% (CAGR 3%); and neck MRA increasing by 52% (CAGR 4%).

Ultrasound use meanwhile declined, with a decrease specifically of carotid duplex ultrasound of 8% (CAGR -1%).

The highest increases per 1000 ED visits were seen with CTA of the head and neck among those aged 65 or older, with an increase of 1011% (CAGR 24%). Head and neck CT in the 65+ age group increased during the same period by 48% (CAGR 4%).

The increases did not appear to be associated with any particular indication, Merdan noted.

"We attempted to look for a finding related to indication-specific growth, [but] we did not find that any one specific indication, such as cerebral infarction or syncope, seemed to be the cause of such increased growth in CT and CTA," Merdan said.

With only claims data available, the authors were not able to show how often the imaging utilization was in accordance with clinical guidelines.

They concluded that the leading causes for the increases were likely greater access to, and understanding of, the technology.

"We speculated that general CT and CTA availability and provider-related trends, such as better familiarity, were the cause of such growth," Merdan said.

However, she added that "the findings are purely descriptive and will hopefully inspire future studies to examine causes more carefully."

Dr Arjun Venkatesh

Commenting for Medscape Medical News, emergency medicine specialist Arjun K. Venkatesh, MD, MBA, MHS, said that in terms of neuroimaging in the ED, clinical guidelines have indeed often supported increased neuroimaging utilization in the hopes of improving outcomes, particularly for stroke.

"Clinical guidelines between 2007 and 2017 have often recommended more neuroimaging for conditions like stroke/TIA or promoted pathways such as serial CT imaging in the ED to avoid hospitalization," said Venkatesh, chief of the Section of Administration in the Department of Emergency Medicine at Yale University, New Haven, Connecticut.

"In both cases, more imaging may represent care of more clinical benefit or higher value," he said.       

Concerns of medical imaging overuse, in general, have surrounded issues including radiation exposure (with CT), incidental findings, and costs. Campaigns such as the Choosing Wisely initiative have strived to tackle the issues, focusing on unnecessary medical tests and "low-value" care.

In a recent study addressing Choosing Wisely concerns, Venkatesh and colleagues reported finding wide variation in imaging use at EDs, but report significant reductions in use at EDs participating in the Emergency Quality Network (E-QUAL) Avoidable Imaging Initiative.

Meanwhile, in a separate study, Venkatesh's team found increases in ED visits were occurring just as primary and specialty care visits declined — also possibly explaining the rise in ED neuroimaging.

"Due to [various] administrative hurdles, more imaging for urgent and nonemergent conditions may be occurring in the ED as overburdened PCPs and specialists send patients to the ED for imaging access off-hours or with less paperwork," Venkatesh told Medscape.

However, the increased ED utilization and imaging can "identify diagnoses or exclude high-risk diagnoses prior to hospitalization and [result in] fewer hospital admissions and more efficient care delivery," Venkatesh noted.

Rade B. Vukmir, MD, JD, an emergency and critical care medicine specialist based in Pittsburgh, Pennsylvania, and spokesperson for the American College of Emergency Physicians (ACEP), underscored that the likely overriding reason for increased CTA use in the ED is simply that it saves lives.

"The fact is that a stroke is one of the costliest burdens to medical care that exists, and if you were to say to someone, 'You can use a watch and wait approach' or have CTA now possibly to diagnose and treat the cause of the stroke, it's not a tough choice," he told Medscape Medical News.

Although the majority of strokes — about 80% involving the anterior circulation — often present with symptoms that are apparent, the remaining 20% have subtle signs that may not be obvious, and in those cases, immediate neuroimaging can be critical, Vukmir noted.

"In the past, those cases could be missed, but now we can pick them up because we have this highly effective test in addition to clinical acumen alone," he said.

In their study, the authors made note of the possible role of financial incentives in neuroimaging decisions.

"Conscious or unconscious bias regarding financial incentives may influence imaging decisions," they write, noting, for instance, reports that providers sometimes paid more for MRIs from private insurance vs Medicare Advantage plan.

Vukmir strongly disagreed with that suggestion.

"There is no practicing emergency provider that typically has any idea of the patient's insurance status, or the cost of neuroimaging, nor would you ever use cost as a decision-making tool," he emphasized. "The suggestion that the calculation of cost as a profit motive [that] changes the testing decisions in the ED could not be farther from the truth."

There are, however, legal concerns that can compel efforts to err on the side of caution and cover all bases amid potential malpractice allegations, Vukmir added.

"There is a significant concern of litigation that can influence a defensive approach, and that tends to be region-dependent," he said. "But at the end of the day, the goal in the ED is to take care of anyone that presents, with or without insurance, and the science should decide who receives the test or not."

The study authors, Venkatesh, and Vukmir have disclosed no relevant financial relationships.

American Journal of Roentgenology. Published online August 4, 2021. Abstract


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